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MENISCAL INJURYMRI and Arthroscopic Findings
Rawiwan Pattaweerakul
Naresuan University Hospital
Meniscus
Posterior Roots
AHAH
PH PH
Anterior Roots
LateralMeniscus
MedialMeniscus
Meniscus Normal Meniscus
Normal Meniscus Normal Meniscus (LM)
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Normal Meniscus (LM) Normal Meniscus (MM)
Normal Meniscus (MM) Surrounding anatomy
• Transverse meniscal ligament• Meniscal femoral ligament (MFL)• Popliteomeniscal fascicles• Oblique meniscomeniscal ligament
Anterior Transverse Meniscalligament• Anterior Transverse Meniscal ligament
• Connects and stabilizes anterior horns of the meniscus
Anterior Transverse Meniscalligament
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Meniscofemoral ligament(MFL)• Originate from the posterior horn of the lateral
meniscus and insert onto the lateral aspect of themedial femoral condyle
• Humphry (aMFL)• Wrisberg (pMFL)
Meniscofemoral ligament(MFL)
Humphry ligament (aMFL) Wrisberg ligament (pMFL)
Popliteomeniscal fascicles
• Popliteomeniscal fascicles• Mimic a peripheral posterior horn flap tear• A tear of posterosuperior fascicle is highly associated
with a tear of lateral meniscus
Popliteomeniscal fascicles
Oblique meniscomeniscalligament
• Connects the anterior horn of the one meniscus with theposterior horn of the contralateral meniscus
• Present in 1-4% of knees• Mimic a centrally displaced meniscal fragment
Oblique meniscomeniscalligament
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MRI criteria for diagnosis atear• Meniscal distortion without prior surgery• Increased intrasubstance signal intensity
unequivocally connecting the articular surface• “two-slice-touch” rule
De Smet AA et al. AJR Am J Roentgenol 2006;187(4):911–914.
Meniscal tear classification
• Horizontal tear• Longitudinal tear• Radial tear• Root tear• Complex tear• Displaced tear• Bucket-handle tear• Fraying
Horizontal tear Horizontal tear
• MRI shows a horizontally oriented line of high SIthat contacts the meniscal surface or free edge.
• Parameniscal cyst formation is associated withcomplete tear
Ferrer-Roca O, Vilalta C.Clin Orthop Relat Res 1980;(146):301–307.
Lt Knee/Horizontal Tear of LM Horizontal Tear (LM, Lt. Knee)
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Parameniscal Cyst Longitudinal tear
Longitudinal tear
• MRI shows a vertical oriented line of high SI thatcontacts one or both articular surface
• It have a propensity to involve the peripheral thirdof the meniscus and posterior horn
• There is a close association between peripherallongitudinal tear and ACL torn, specificity, 90% ofMM and 83% of LM.
De Smet AA, Graf BK.AJR Am J Roentgenol 1994;162(4):905–911.
Longitudinal Tear (LM, Rt.knee)
Longitudinal Tear (LM, Rt.knee)
Longitudinal Tear (LM, Rt.knee)
Undersurface
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Longitudinal Tear (LM, Rt.knee)
Undersurface
Radial tear
Radial tear
• Commonly involve the posterior horn of the MM orjunction of anterior horn and body of the LM.
• MRI shows a cleft oriented perpendicular to thefree edge.
• Variable appearances• Truncated triangle• Cleft• Marching cleft• Ghost meniscus
Radial tear
Radial tear Radial Tear (LM, Rt. Knee)
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Complex tear
• A combination of radial, horizontal and longitudinalcomponents
Complex/radial tear
Complex/Radial Tear(LM, Lt.Knee) Bucket-handle tear
Bucket-handle tear
• Occurs frequently in MM
• MRI signs• An absent bow tie• A fragment within the intercondylar notch• A double PCL• A double anterior horn or flipped meniscus• Disproportionally small posterior horn
Shakespeare DT, Rigby HS.Bone Joint Surg Br 1983;65(4):383–387.
Dorsay TA, Helms CA. Skeletal Radiol 2003;32(5):266–272.
Magee TH, Hinson GW. Skeletal Radiol 1998;27(9):495–499.
Haramati N, et al. Skeletal Radiol 1993;22(4):273–277.
Rt Knee/Bucket Handle Tear ofLM
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Bucket Handle Tear (LM,RtKnee) Double PCL sign
Fraying
• At arthroscopy, fraying is defined as surfaceirregularity along the meniscal free edge without adiscrete tear.
• MRI findings• At the free edge shows loss of its sharp tapered central
edge.• At the posterior root shows subtle, ill-defined,
horizontally oriented increased intrameniscal SIcontacting the articular surface
• DDx shallow partial-thickness tear, fraying and surroundingsynovitis
Jie C. Nguyen et al.Radiographics. 2014 Jul-Aug;34(4):981-99
Fraying
Fraying
INDIRECT SIGN OFMENISCAL TEAR
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Indirect sign of meniscal tear
• Parameniscal cyst• Meniscal extrusion• Subchondral marrow edema
Parameniscal cyst
• Direct contact to the meniscus or via a fluid track,• Typically contains a horizontal tear component
Parameniscal Cysts Meniscal extrusion
• Peripheral margin of the meniscus extends ≥ 3 mmbeyond the edge of tibial plateau
• Close association between meniscal extrusion androot tear
• 76% of medial root tears have extrusion• 39% of extrusion have medial root tear
• Can also be seen with complex tear, large radialtear and severe meniscal degeneration.
Costa CR, et al.AJR Am J Roentgenol 2004;183(1):17–23.
Meniscal extrusion
MENISCALCONTUSION
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Meniscal contusion
• Occurs when the meniscus gets trapped betweenthe tibia and the femur during a traumatic event
• Indistinct and amorphous increased signal intensityin the periphery of the meniscus
Cothran RL Jr, et al.AJR 2001;177:1189–1192
ANATOMICALVARIATION AND
PITFALLS
Anatomical variation andpitfalls• Discoid meniscus• Meniscal flounce• Meniscal ossicle• Chondrocalcinosis
Anatomical variation andpitfalls• Discoid meniscus
• The variant: ring-shape meniscus with connectionbetween the roots can mimic a medially displacedmeniscal fragment
• Meniscal flounce• Meniscal ossicle• Chondrocalcinosis
Ring-shaped discoid meniscus Anatomical variation andpitfalls• Discoid meniscus• Meniscal flounce
• A rippled appearance of the free nonanchored inneredge of the MM
• Typically, secondary to flexion of the knee andredundancy of the free edge of the MM
• Meniscal ossicle• Chondrocalcinosis
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Meniscal Flounce (MM, Lt.Knee)
Meniscal Flounce (MM, Lt.Knee)
Anatomical variation andpitfalls• Discoid meniscus• Meniscal flounce• Meniscal ossicle
• A predilection for the posterior horn of the MM• Increased SI can mimic a tear
• Chondrocalcinosis
Jie C. Nguyen et al.Radiographics. 2014 Jul-Aug;34(4):981-99
Meniscal ossicle
Rakesh Mohankumar, et al.AJR Am J Roentgenol. 2014;203: 1040-1046
Anatomical variation andpitfalls• Discoid meniscus• Meniscal flounce• Meniscal ossicle• Chondrocalcinosis
• Increased SI can mimic a tear
Jie C. Nguyen et al.Radiographics. 2014 Jul-Aug;34(4):981-99
Meniscal chondrocalcinosis
B J Burke, et al.AJR Am J Roentgenol. 1998;170: 69-70.
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